damian

iTrader: (2)

i just purchased a set of 99 spec twins that were said to have 8000 miles on them. they look almost new, the housing looks new, no cracks or even a hint of cracks, however i have a question on the turbos themselves.

I know that the 99 spec are a bit different so i dont want to compare them to the stockers just yet, but here is my question:

there is NO font to back shaft play, so they are both good there, but both have a little lateral shaft toggle, it is very minimal and a bit of play is normal, so i wasnt to worried, HOWEVER, they dont spin as easily as my stockers and if I push them to the side they will hit the side wall enough to make difficult to spin the turbo.... that scares me....but if you measure the play its only like less than 1/32 of an inch? so maybe that is supposed be how it behaves...and maybe they dont spin well right now is because they are bone dry, no oil in there at all...so maybe with a touch of oil they will spin as easy as my stockers?

...I know there is a design change on the 99s, like there is a black plastic looking ring on the inside wall so maybe the turbine is supposed to 'kiss' that to make a better seal (i read somthing about that at one point)..

but in any case i need to hear from 99 spec guys if that is normal or these things are both shot... I want to do some research before getting back to the seller.

7racer

Damian,

mine where new and do have the black plastic ring. However, I haven't pulled my turbos off (hope to never do for a long time). New, there was no shaft play what so ever.

damian

iTrader: (2)

>>New, there was no shaft play what so ever.

thanks for the reply, so are you saying no lateral shaft play at all on the new ones you got?

7racer

Not that I can remember. I remember playing with it because of the supposed benefits of the self abraiding seal...that was the hyped "zero clearance"

see read about it here:
http://www.rx7.net.nz/newrx7.htm

David Beale

They have an abraidable seal on the intake side from the compressor wheel outside edge to the housing. If you try to spin it you will hit the seal. That is probably why it seems to have more friction. When the oil pressure is up and it's being spun properly from the turbine wheel (the exhaust wheel) it doesn't touch the seal and would spin just as easily as the older design.

When new the seal hasn't been abraided so there will be no play. The new ones have to "break in" before they will spin freely. Doesn't take more than a few minutes of operation.

I suspect your limited play is normal for one that has been abraided (run).

damian

iTrader: (2)

thanks David, that is the info I wanted to hear :-)

damian

iTrader: (2)

by the way, i want to mention that the person I purchased them from was great to deal with, answered all my questions, had pics, and so far the turbos really do look in 'like new' condition and for a great price too..... so this was not a thread I started because I did not trust him, rather, I needed to be educated to the nuances of the 999 spec turbos :-)

I'll take some pics and actually measure the free play space with one of those spacer tools and post the info later, im sure they are fine.

Rated R1

So, who did you buy them from?

damian

iTrader: (2)

the guy in this thread:

https://www.rx7club.com/showthread.php?t=337244

Rated R1

Thanks!! I haven't seen that good of pics of the 99 twins before. They are a lot more different then I thought. Be sure to let us know how they work out for you!